mbox series

[0/5] AMD Pstate driver Urgent Change

Message ID 20221117024955.3319484-1-Perry.Yuan@amd.com
Headers
Series AMD Pstate driver Urgent Change |

Message

Yuan, Perry Nov. 17, 2022, 2:49 a.m. UTC 
  The patchset changed amd-pstate driver as built-in type to resolve the
driver loading sequence problem, otherwise the acpi-cpufreq driver will
be loaded as the default cpufreq scaling driver instead of amd-pstate.

Some new kernel parameters are added to allow user to disable pstate driver
and load driver with passive mode which use governors to do the
frequency scaling control.

* `amd_pstate=disabled` or no parameters will not load pstate driver.
* `amd_pstate=passive` will load pstate driver with passive mode.

Set the `amd_pstate` driver disabled by default because of performance
degradation on a number of AMD ASICs in the passive mode driver,
especially the shared memory support processors.

EPP support for the amd_pstate driver is under review. With EPP support,
the said performance issue is resolved. Once that gets upstream,
the `active` mode amd_pstate_epp driver may be enabled by default.

Perry Yuan (4):
  cpufreq: amd-pstate: change amd-pstate driver to be built-in type
  cpufreq: amd-pstate: add amd-pstate driver parameter for mode
    selection
  Documentation: amd-pstate: add driver working mode introduction
  Documentation: add amd-pstate kernel command line options

Wyes Karny (1):
  cpufreq: amd-pstate: cpufreq: amd-pstate: reset MSR_AMD_PERF_CTL
    register at init

 .../admin-guide/kernel-parameters.txt         | 11 +++++
 Documentation/admin-guide/pm/amd-pstate.rst   | 30 +++++-------
 drivers/cpufreq/Kconfig.x86                   |  2 +-
 drivers/cpufreq/amd-pstate.c                  | 49 +++++++++++++------
 4 files changed, 59 insertions(+), 33 deletions(-)

Comments

Huang Rui Nov. 17, 2022, 5:35 a.m. UTC | #1 
On Thu, Nov 17, 2022 at 10:49:50AM +0800, Yuan, Perry wrote:
> The patchset changed amd-pstate driver as built-in type to resolve the
> driver loading sequence problem, otherwise the acpi-cpufreq driver will
> be loaded as the default cpufreq scaling driver instead of amd-pstate.
> 
> Some new kernel parameters are added to allow user to disable pstate driver
> and load driver with passive mode which use governors to do the
> frequency scaling control.
> 
> * `amd_pstate=disabled` or no parameters will not load pstate driver.
> * `amd_pstate=passive` will load pstate driver with passive mode.
> 
> Set the `amd_pstate` driver disabled by default because of performance
> degradation on a number of AMD ASICs in the passive mode driver,
> especially the shared memory support processors.
> 
> EPP support for the amd_pstate driver is under review. With EPP support,
> the said performance issue is resolved. Once that gets upstream,
> the `active` mode amd_pstate_epp driver may be enabled by default.
> 
> Perry Yuan (4):
>   cpufreq: amd-pstate: change amd-pstate driver to be built-in type
>   cpufreq: amd-pstate: add amd-pstate driver parameter for mode
>     selection
>   Documentation: amd-pstate: add driver working mode introduction
>   Documentation: add amd-pstate kernel command line options
> 
> Wyes Karny (1):
>   cpufreq: amd-pstate: cpufreq: amd-pstate: reset MSR_AMD_PERF_CTL
>     register at init

Series are Acked-by: Huang Rui <ray.huang@amd.com>

Hi Rafeal,

These series are the fixes for our new processors. Would you mind to merge
them into pm-6.1-rc6 or pm-6.1-rc7?

Thanks,
Ray